Fitness to drive and accident risk assessment in patients with Obstructive Sleep Apnoea Syndrome(OSAS)

Obstructive Sleep Apnoea Syndrome (OSAS) is the most common form of sleep disordered breathing characterised by snoring, apnoeic episodes, sleep fragmentation at night and excessive daytime sleepiness. Some patients with OSAS are at increased risk of being involved in road traffic accidents (RTA). Compared to other individuals, some OSAS patients are at 2-6 times at risk of having a RTA. Clinicians are not only involved in screening, diagnosing, managing patients with OSAS but are often asked to make recommendations about fitness to drive and this is likely to be inconsistent in the absence of objective criteria. Some clinicians advise against driving in high-risk patients and in certain situations inform the licensing authorities. Driving simulators have been used in the research setting to predict fitness to drive in various situations. Many studies have used simple simulators that were unrealistic. The Institute for Transport Studies at the University of Leeds has developed a sophisticated driving simulator (UoLDS). Alongside this, a PC-based simulator (Mini University of Leeds Driving Simulator, MUoLDS) has been developed using the same software. Using continuously measured variables it has been possible to identify, with a high degree of accuracy, a subset of patients with OSAS who fail a simulated driving test. This has the potential to identify at-risk drivers and improve the reliability of a clinician’s decision-making. Before the MUoLDS can become useful as a clinical tool there are a number of further questions to be answered and the thesis will address some of these.